Glint Removal From Multispectral Imagery Over Clear Water

Abstract

Abstract : Multispectral imagery over clear water provides information about the seafloor, in shallow coastal waters up to 20 m, which can be used to model depth, bottom type and seafloor texture. Glint, or specular reflection off the sea surface, is often present, thus masking the effect of bottom reflectance on algorithms which model the seafloor. Glint can be effectively removed in cases where the water is very clear due to the high correlation of glinted surfaces over multiple bandwidths. This information, used in conjunction with differences in attenuation between the visible and infrared portions of the electromagnetic spectrum, were used by Lyzenga to derive a method for glint removal. The technique presented here expounds on that method by adding a texture technique to break out bright areas, such as white sandy shoals, that sometimes alias as glint, but have different texture, and by adding a quadratic term to the correction model.